Done

Problem 2 BigCountries.py

@@ -0,0 +1,5 @@
+import pandas as pd
+
+def big_countries(world: pd.DataFrame) -> pd.DataFrame:
+    df = world[(world['area']>=3000000) | (world['population']>=25000000)]
+    return df[['name','population','area']]

Problem 3 Recyclable and Low Fat Products.py

@@ -0,0 +1,4 @@
+import pandas as pd
+
+def find_products(products: pd.DataFrame) -> pd.DataFrame:
+    return products[(products['low_fats']=='Y') & (products['recyclable']=='Y')][['product_id']]

Problem 4 Customer Who Never Order.py

@@ -0,0 +1,5 @@
+import pandas as pd
+
+def find_customers(customers: pd.DataFrame, orders: pd.DataFrame) -> pd.DataFrame:
+    return customers[~customers['id'].isin(orders['customerId'])][['name']].rename(columns ={'name':'Customers'})
+

README.md

@@ -1,6 +1,6 @@
 # Pandas1
 
-1 Problem 1 : Make a Pandas DataFrame with two-dimensional list	(	https://www.geeksforgeeks.org/make-a-pandas-dataframe-with-two-dimensional-list-python/)
+1 Problem 1 : Make a Pandas DataFrame with two-dimensional list	(	https://www.geeksfor    geeks.org/make-a-pandas-dataframe-with-two-dimensional-list-python/)
 
 2 Problem 2 :Big Countries	(	https://leetcode.com/problems/big-countries/ )